Problem: Expand and combine like terms. $(9y^5+2)^2=$
We can expand this expression using the "perfect square" pattern (where $P$ and $Q$ can be any monomial): $(P+Q)^2=P^2+2PQ+Q^2$ $\begin{aligned} &\phantom{=}\left(9y^5+2\right)^2 \\\\ &=\left(9y^5\right)^2+2\left(9y^5\right)\left(2\right)+\left(2\right)^2 \\\\ &=81y^{10}+36y^5+4 \end{aligned}$